Good intentions that fail to cope with the main point in CQT: a comment on Palmatier and Rovner (2015)

Palmatier and Rovner (2015) made an important attempt to bridge the gap between the accumulated practical experience in field polygraphy, including the increased body of scientific work done by scientists and practitioners within the field and the academic attitude towards polygraph testing. They say that the two main polygraph methods, the Concealed Information Test (CIT) and the Comparison Question Test (CQT) though using different protocols, in the end deal with lying and can be explained under the same theoretical concept. They proposed that the Preliminary Process Theory (PPT) developed by Barry in a totally different context, should be adopted for the construct validity of psychophysiological detection of deception (polygraph). The current commentary argues that even if in the end, the examinee lies (or tells the truth) in both types of test, it does not mean that lying has been measured directly. Instead, the tests represent the efforts to deduce about veracity in the absence of any specific physiological feature representing deception. Moreover, the two methods are not just two different protocols; rather, their underlying rationales are different and cannot be reduced to a comprehensive common construct. With regard to PPT, it is pointed out that the explanation of the most important element in CQT, namely, the differential relative significance that truthful and deceptive examinees are expected to attribute to relevant vs. comparison questions, is out of its scope and therefore, unlike the authors' suggestion its place as a cornerstone in the construct validity of polygraph testing is questionable.